Electrophoretic toothbrush



Nov. 26, 1968 w. REYNOLDS 3,412,731

ELECTROPHORETIC TOOTHBRUSH Filed March 29, 1965 INVENTOR. LUTHER HfREV/VOL 0S wfzz ATTORNEY United States Patent 3,412,731 ELECTROPHORETICTOOTHBRUSH Luther W. Reynolds, 254 S. 16th St., Philadelphia, Pa. 191023,412,731 Patented Nov. 26, 1968 "ice silver (+0.80), the cell has atheoretical voltage of 2.35 volts. Thus, the highest voltages areobtained by using metals spaced the furtherest apart on theelectromotive series.

Filed Mar. 29, 1965, $61. No. 443,185 5 TABLE I 3 Claims. (Cl. 128-1721)Normal electrode potential (volts) Element: referred to hydrogenelectrode K 2.92 ABSTRACT OF THE DISCLOSURE N 2 71 An electrophoretictoothbrush is described having Mg connecting electrodes in the handleand brush head which Zn provides a flow of current when the head isinserted Fe in the users mouth so that fluoride ions when present 511 inthe users mouth will flow to the users teeth. Similar- Pb ly, thiselectrical source is described as useful to power 15 H other devicessuch as a radio transmitter and an electric Bi wrist watch. Hg +0.80 Thepresent invention relates to a source of electrical +0'80 power, andmore particularly to an electrical power source I have discovered that,when two electrodes of different for lo power o erated portable de i emetals on the electromotive series are placed in spaced re- With theadvent of miniaturized electrical components ation on the epidermalsurface of an animal, including and low power operated electricalcircuits, there has a human, the body of the animal acts as a solidelectrolyte been developed many portable electrical devices, such and acell is created which provides a low voltage curas radio receivers,radio transmitters, toothbrushes, hearrent. The metals for suchelectrodes should be as far ing aids, watches, shavers, etc. However,all of the devices apart on the electromotive series as possible so asto have one common drawback. The power source for operatprovide maximumvoltage, but must be metals which do ing these devices is a batterywhich has a limited usenot adversely react with the skin of the animal;for examable life. Thus, the batteries must be replaced from time ple,electrodes of silver and magnesium. Although solid to time, or, ifrechargeable, must be accompanied by metal electrodes are preferred, theelectrodes may also devices for recharging the battery. The need forreplacing be organic or inorganic compounds of the metals. the batteriesor for a special device to recharge the Although, as stated above, thetheoretical calculated battery not only adds to the expense of thedevice, but EMF for a silver-magnesium couple is 2.35 volts, exmakes thedevice unreliable since it cannot always be periments showed that theopen circuit voltage for this determined with certainty when the batterywill go bad. couple when attached to the human skin is 1.2 to 1.4Therefore, it is desirable to have a power source for such volts. Thisreduction in volta is believed to be Caused portable devices which isreliable, has a long life and is by an imperfect electrical function atthe interface of inexpensive. the electrodes and the epidermis, and bythe fact that An object of this invention is the provision of an theepidermis does not provide a uniform electrolyte. electrophoretictoothbrush. The electrical power obtainable with a silver-magnesiumOther objects will appear hereinafter. pair of electrodes secured inspaced relation on the human For the purpose of illustrating theinvention, there is skin was calculated by connecting konwn resistancesacross shown in the drawings forms which are presently prethe circuitand measuring the voltage drop. From these ferred; it being understood,however, that this invention 4? data, the current was calculated. Thecurrent multiplied is not limited to the precise arrangements andinstrua by the voltage gave the power output. It was found thatmentalities shown, a maximum power of 250 micro watts was obtained atFIGURE 1 is a schematic view of an audio transmitter 0.5 volt and 500micro amps. having the power source of the present invention. It hasbeen found that the size of the electrodes and FIGURE 2 is a view of anelectric wrist watch having the spacing between the electrodes affectsthe power outt-he power source of the present invention. put obtainable.Table II shows the variation in the power FIGURE 3 is a view of anelectrophoretic toothbrush output with variations in the size of theelectrodes and having the power source of the present invention. thespacing between the electrodes. The electrodes used In general, theelectrical power source of the present were asilver-magnesium couple. Itcan be seen from Table invention is based on the principal that, whentwo dif- II that the larger the area of the electrodes and the ferentmetals of the electromotive sources are placed in closer they are, thehigher the power output.

TABLE II Electrode Voltage Current Resistance Power Location area(volts) (micro (ohms) (micro (cm!) amps) (K. watts) Forearm 1 cm. apart24. 5 0. 5 500 l 250 Forearm 4 cm. apart 24. 5 0. 24 510 475 120 One oneach arm 24.5 0.45 450 1 202 Forearm 2 cm. apart 9. 6 0.30 300 1 90 anelectrolyte, there is created a cell which provides an electricalcurrent. Table I is an abbreviated list of these metals. When a cell ismade of two of these metals in a uniform electrolyte, the EMF of thecell is determined from the individual potential values of the metalsused. For example, if the metals are magnesium (-l.55) and Referring toFIGURE 1 of the drawing, there is shown an audio transmitter 10 usingthe power source of the present invention. The electrical circuitry ofthe transmitter 10 may be any well-known audio transmitter circuit whichwill operate from a low power source. The power input terminals of thetransmitter 10 are connected by wires 12 and 14 to flat disc or stripelectrodes inserted on the inner surface of straps 16 and 18. As statedabove, the electrodes are of two different metals of the electromotiveseries, such as silver and magnesium. The straps 16 and 18 are securedin spaced relation around the arm 20 of a person with the electrodecontacting the surface of the skin. The transmitter 10 is provided witha microphone 22 and an aerial 24 in the manner well known in the art.The signal from the transmitter 10 can be received by a radio, generallyindicated as 26, which is tuned to the frequency of the transmitter.

Referring to FIGURE 2, there is shown an electrical wrist watch 28 usingthe power source of the present invention. Wrist watch 28 can be of anywell-known construction for a watch operated by a battery. However,instead of a battery, a pair of electrodes 30 and 32 of the presentinvention were secured on the inner surface of the straps 34 and 36respectively. The electrodes 30 and 32 are connected to the power inputterminals of the electrical circuit operating the watch by wires 38 and40 which extend along the straps 34 and 36 and through the case of thewatch. Thus, when the watch 28 is secured to the users arm, theelectrodes 30 and 32 contact the skin of the user at spaced points tocomplete the electrical circuit and provide the power to operate thewatch.

Referring to FIGURE 3, there is shown an electrophoretic toothbrush 42which uses the power source of the present invention. It is known thatwhen a direct electrical current is passed through a solution, the ionsin the solution will migrate toward the side of the charge opposite tothat of the ions. It is also known that fluorides are effective toprevent decay of teeth and that the better the penetration of thefluorine into the teeth, the more effective the fluoride is. Anelectrophoretic toothbrush is a toothbrush which provides an electricalcurrent through the fluoride so as to cause migration of the fluorineions into the teeth.

Toothbrush 42 of the present invention comprises a handle 44 having ahead 46 at one end thereof. The handle 44 and head 46 are of anelectrically insulating material, such as a plastic. Bristles 48 areprovided on the head 46. A negative electrode 50, such as a strip ofmagnesium, is secured to the surface of the head 46 at the bottom of thebristles 48. A positive electrode 52, such as a strip of silver, issecured to the end of the handle 44. A wire 54 extends along the handle44 and electrically connects the positive electrode 52 and the negativeelectrode 50.

To use the toothbrush 42, toothpaste containing fluoride is placed onthe bristles 48. The user holds the handle 44 so that the positiveelectrode 52 contacts the skin of the users hand. When the head 44 ofthe toothbrush 42 is placed in the users mouth, the negative electrode50 contacts the user so as to complete the electrical circuit andprovide a flow of current through the fluoride toothpaste. Thus, thefluorine ions migrate from the bristles to the positive charged teeth soas to cause greater contact between the fluorine and the teeth. It isbelieved that the flow of electricity also stimulates the gingiva andprovides a beneficial effect.

The power source of the present invention can be used to operate anyother electrical devices which operate on low power. Since the powersource of the present invention includes an animal, such as a human, itis preferably used for portable devices. or any such electrical devicesit is only necessary to replace the batteries which are normally used tooperate the device with a pair of the electrodes of the presentinvention. The electrodes are connected to the power input terminals ofthe electrical circuit of the device and are provided with means, suchas straps, for using the electrodes to the skin of the animal. The powersource of the present invention has the major advantage that it isextremely reliable in that it provides a steady output and has a longlife.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention.

I claim:

1. An electrophoretic toothbrush comprising a handle of an electricalinsulating material, a head of an electrical insulating material at oneend of said handle, bristles secured to said head and extending from asurface of said head, an electrode secured to said handle, a secondelectrode secured to said surface of said head, said electrodes being ofdifferent metals of the electromotive series, and means extending alongsaid handle and electrically connecting said electrodes to each other.

2. An electrophoretic toothbrush in accordance with claim 1 in which oneof said electrodes contains silver and the other electrode containsmagnesium.

3. An electrophoretic toothbrush in accordance with claim 2 in which theelectrode on the handle contains silver.

References Cited UNITED STATES PATENTS 415,274 11/1889 Kane 128-381 XR5/1958 Kauai 128-172.1

FOREIGN PATENTS 3/1963 Switzerland.

